juju/juju — pull request #1102 by fwereade (2014-11-11 08:33:49+00:00)
Title: uniter: move action validation into context factory

Main benefit:
* untangled much of the ugliness/confusion in uniter.runHook
Main drawback:
* dropped handling for nonexistent actions
Reason I don't care about the above:
* it was incomplete and entirely untested
Driveby improvement:
* uniter no longer takes the execution lock until it's got a valid context to run in